package com.remark.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.remark.dto.Result;
import com.remark.dto.ScrollResult;
import com.remark.dto.UserDTO;
import com.remark.entity.Blog;
import com.remark.entity.Follow;
import com.remark.entity.User;
import com.remark.mapper.BlogMapper;
import com.remark.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.remark.service.IFollowService;
import com.remark.service.IUserService;
import com.remark.utils.RedisConstants;
import com.remark.utils.SystemConstants;
import com.remark.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.remark.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.remark.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;

    @Resource
    private IFollowService followService;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryBlogById(Long id) {
        // 查询blog
        Blog blog =getById(id);
        // 如果查询不到，返回错误信息
        if(blog==null)
        {
            return Result.fail("博客不存在");
        }
        //查询blog有关的用户
        Long userId = blog.getUserId();//获取博客的作者id
        User user=userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
        //查询blog是否被点赞
        //判断当前用户是否点赞
        UserDTO user1=UserHolder.getUser();
        if (user1 == null) {
            //用户未登录，无需查询是否点赞
            return Result.ok(blog);
        }
        //获取当前登录的用户id
        Long userId1 = user1.getId();
        String key=BLOG_LIKED_KEY+id;
        Double score=stringRedisTemplate.opsForZSet().score(key,userId1.toString());
        blog.setIsLike(score!=null);
        return Result.ok(blog);
    }

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            Long userId = blog.getUserId();//blog的作者id
            User user=userService.getById(userId);
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
            //判断当前用户是否点赞
            UserDTO user1= UserHolder.getUser();
            if (user1 == null) {
                //用户未登录，无需查询是否点赞
                return;
            }
            Long userId1 = user1.getId();
            //获取当前登录的用户id
            String key=BLOG_LIKED_KEY+blog.getId();
            Double score=stringRedisTemplate.opsForZSet().score(key,userId1.toString());
            blog.setIsLike(score!=null);
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBlog(Long id) {
        //获取登录用户
        Long userId= UserHolder.getUser().getId();
        //判断当前登录用户是否已点赞
        String key=BLOG_LIKED_KEY+id;
        Double score=stringRedisTemplate.opsForZSet().score(key,userId.toString());
        //如果未点赞，可以点赞
        if(score==null){
            //数据库点赞数+1
            boolean isSuccess=update().setSql("liked=liked+1").eq("id",id).update();
            //保存用户到Redis的set集合
            if(isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }
        else{
            //如果点赞过，取消点赞
            //数据库点赞数-1
            boolean isSuccess=update().setSql("liked=liked-1").eq("id",id).update();
            //把用户从Redis的set集合移除
            if(isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = RedisConstants.BLOG_LIKED_KEY +id;
        //1.查询top5的点赞用户 zrange key 0 4
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5==null || top5.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        //2.解析出其中的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        //3.根据用户id查询用户
        String idStr = StrUtil.join(",", ids);
        List<UserDTO> userDTOS = userService.query()
                .in("id",ids)
                .last("ORDER BY FIELD(id,"+idStr+")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4.返回
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //获取登录用户
        UserDTO user=UserHolder.getUser();
        blog.setUserId(user.getId());

        // 检查并设置shop_id，避免数据库错误
        if (blog.getShopId() == null) {
            blog.setShopId(SystemConstants.DEFAULT_SHOP_ID); // 使用常量设置默认商铺ID
        }

        //保存探店笔记
        boolean isSuccess = save(blog);
        if(!isSuccess){
            return Result.fail("新增笔记失败!");
        }
        //查询笔记作者的所有粉丝 select * from tb_follow where follow_user_id = ?
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        //推送笔记ID给所有粉丝
        for(Follow follow:follows){
            //获取粉丝id
            Long userId=follow.getUserId();
            //推送
            String key=FEED_KEY+userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2.查询收件箱 ZREVRANGEBYSCORE key Max Min LIMIT offset count
        String key = FEED_KEY+userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 3);
        //2.1.非空判断
        if(typedTuples==null || typedTuples.isEmpty()){
            return Result.ok();
        }
        //3.解析数据：blogId、minTime(时间戳)、offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for(ZSetOperations.TypedTuple<String> tuple:typedTuples){
            //4.1.获取id
            String idStr = tuple.getValue();
            ids.add(Long.valueOf(idStr));
            //4.2.获取分数
            long time = tuple.getScore().longValue();
            if(time == minTime){
                os++;
            }else{
                minTime = time;
                os=1;
            }
        }
        //4.根据id查询blog
        String idStr = StrUtil.join(",",ids);
        List<Blog> blogs = query().in("id",ids).last("ORDER BY FIELD(id,"+idStr+")").list();
        for (Blog blog : blogs) {
            String key1=BLOG_LIKED_KEY+userId;
            Double score=stringRedisTemplate.opsForZSet().score(key1,userId.toString());
            blog.setIsLike(score!=null);
            User user = userService.getById(blog.getUserId());
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
        }
        //5.封装并返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);
        return Result.ok(r);
    }
}
